#include <stdio.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <signal.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/un.h>
#include <string>
#include <fstream>
#include <iostream>

using namespace std;

const int BUFFER_SIZE = 1024;
struct sockaddr_in serv_addr;
struct sockaddr_in cli_addr;
int sockInet;           //Socket
int newSockInet;        //New socket descriptor

string findWords(string words, string fileName) {
    ifstream inputFile(fileName.c_str());
    string line;
    string result = "";
    while (getline(inputFile, line)) {
        if (line.find(words) != string::npos) {
        result.append(line);
        result.append("\n");
            }
        }
        inputFile.close();
        return result;
}

string acceptString(string socketName){
    int sockfd, servlen,n;
        struct sockaddr_un  serv_addr;

    bzero((char *)&serv_addr,sizeof(serv_addr));
        serv_addr.sun_family = AF_UNIX;
        socketName.copy(serv_addr.sun_path, socketName.size());
        servlen = strlen(serv_addr.sun_path) + sizeof(serv_addr.sun_family);
        if ((sockfd = socket(AF_UNIX, SOCK_STREAM,0)) < 0)
            printf("Error creating socket client\n");
        while (true) {
            if (connect(sockfd, (struct sockaddr *) &serv_addr, servlen) >= 0)
                    break;
        }
        char buffer[BUFFER_SIZE];
        n=read(sockfd, buffer, BUFFER_SIZE);
        close(sockfd);
        shutdown(sockfd,1);
        return string(buffer);
}

void sendString(string socketName, string toSend) {
        int sockfd, newsockfd, servlen;
        socklen_t clilen;
        struct sockaddr_un  cli_addr, serv_addr;

        if ((sockfd = socket(AF_UNIX,SOCK_STREAM,0)) < 0)
            printf("error on creating socket Server \n");

        bzero((char *) &serv_addr, sizeof(serv_addr));
        serv_addr.sun_family = AF_UNIX;
        socketName.copy(serv_addr.sun_path, socketName.size());
        servlen=strlen(serv_addr.sun_path) + sizeof(serv_addr.sun_family);

        if(bind(sockfd,(struct sockaddr *)&serv_addr,servlen)<0)
            printf("error on binding socket Server \n");
        listen(sockfd,5);
        clilen = sizeof(cli_addr);
        newsockfd = accept(sockfd,(struct sockaddr *)&cli_addr,&clilen);
        if (newsockfd < 0)
                printf("error accepting Server \n");

        const char* buffer = toSend.c_str();
        char newBuffer[BUFFER_SIZE];
        strcpy(newBuffer, buffer);
        newBuffer[toSend.size()] = '\0';
        int n = write(newsockfd, newBuffer, toSend.size()+1);

        shutdown(newsockfd,1);
        close(newsockfd);
        shutdown(sockfd,1);
        close(sockfd);
}

void work(string socketName, string words, string fileName) {
    string found = findWords(words, fileName);
    sendString(socketName, found);
}

int main(int argc, char* argv[]){
    //Create and check socket
    sockInet = socket(AF_INET, SOCK_STREAM, 0);
    if (sockInet < 0) {
        fprintf(stderr, "Server: ERROR opening socket\n");
        return 0;
    }

    //Setting up sockaddr
    serv_addr.sin_family = AF_INET;         //Set adress family
    serv_addr.sin_port = htons(8000);       //Convert and set port
    serv_addr.sin_addr.s_addr = htonl(INADDR_ANY);  //Connect to any

    if (bind(sockInet, (struct sockaddr *)&serv_addr, sizeof(serv_addr)) < 0) {
        fprintf(stderr, "Server: ERROR on binding\n");
        return 0;
    }

    //Set socket to listen state
    listen(sockInet, 1);

    //Accept connection
    socklen_t clilen = sizeof(cli_addr);
        newSockInet = accept(sockInet,(struct sockaddr *) &cli_addr, &clilen);

    if (newSockInet < 0) {
            fprintf(stderr, "Server: ERROR connecting\n");
            return 0;
        } else {
        fprintf(stdout, "Server: Client connected\n");
    }

    char buf[BUFFER_SIZE];
    bzero(buf, BUFFER_SIZE);

    int count = read(newSockInet, buf, BUFFER_SIZE);
        string wordToFind = string(buf).substr(0, count - 1);
    fprintf(stdout, "Server: String accepted \"%s\"\n", wordToFind.c_str());
    if (fork() == 0) {          //Worker1
        work("socket1", wordToFind, "file1.txt");
    } else {
        if (fork() == 0) {      //Worker2
            work("socket2", wordToFind, "file2.txt");
        } else {
            if (fork() == 0) {  //Worker3
                work("socket3", wordToFind, "file3.txt");
            } else {        //Parent
                string result = acceptString("socket1");
                result.append(acceptString("socket2"));
                result.append(acceptString("socket3"));

                const char* buffer = result.c_str();
                        char newBuffer[BUFFER_SIZE];
                        strcpy(newBuffer, buffer);
                        newBuffer[result.size()] = '\0';
                        int n = write(newSockInet, newBuffer, result.size() + 1);

                shutdown(newSockInet, SHUT_RDWR);
                shutdown(sockInet, SHUT_RDWR);
                close(newSockInet);
                close(sockInet);
            }
        }
    }

    remove("socket1");
    remove("socket2");
    remove("socket3");
    return 0;
}